Fuel oil composition having reduced pour point



United States Patent Claims priority, application France Aug. 22, 1960 12 Claims. (Cl. 44-65) This invention relates to petroleum fuel oil compositions which contain a substantial proportion of residual fuel oil. This type of fuel oil may be prepared from a residue obtained from a waxy crude and it is usually necessary to dilute the residue with a gas oil in order to produce a fuel oil whose viscosity is adjusted to specification. Such fuel oils may contain both waxy materials and asphaltenes and their pour points are often too high to permit storage and easy pumping at low temperatures. Some similar fuel oils prepared from naphthenic crudes do not present this drawback.

Many additives are known which are effective in reducing the pour points of lubricating oils and waxy gas oils, but these additives are without any noteworthy effect on the pour points of residual fuel oils, probably because the latter contain asphaltenes which are not present in lubricants and gas oils. Residual fuels are much cheaper than lubricants and it is undesirable to increase the price, e.g. by using an expensive additive or an additive which is expensive at the working concentration.

- The present invention provides fuel oil compositions containing an additive which does not suffer from the above mentioned disadvantages.

According to the invention'a fuel oil composition consists essentially of a small proportion of an'additive dissolved in a base oil, the additive consisting of one or more of the diesters formed between one molecular proportion of a glycol or polyglycol containing 2-10 carbon atoms per molecule and two molecular proportions of a ixture of:

(1) A chlorinated fatty acid and (2) A saturated fatty acid having at least 10, preferably at least 18, carbon atoms per molecule, or a mixture of such acids, or such a mixture containing a small proportion of unsaturated and/or unsaponifiable acids, the mole ratio of (1):(2) being 1: /2-2 and preferably equimolecular and the base oil being a petroleum fuel oil which contains at least a substantial proportion of a distillation residue. Preferably the chlorinated fatty acid is one of the formula CIC H COOH where n is an integer greater than 0 and less than 11, particularly rnonochloracetic acid. The preferred additives are those prepared from monoethylene glycol, diethylene glycol, triethylene glycol and propylene glycol, e.g. the diester formed between one molecular proportion of diethylene glycol and two molecular proportions of an equimolecular mixture of monochloracetic acid and wool grease stearine.

Preferably the fuel oil composition according to the weight of the additive.

Residual petroleum fuel oils usually contain about 20- 80% by weight of the distillation residue which may be either a vacuum residue or an atmospheric residue and mixtures of both types of residue are sometimes used. It is also possible to include most petroleum hydrocarbon materials, e.g. residues from cracking and reforming processes, provided that the final blend has a viscosity and flash point according to specification. Often the blend contains only distillation residues and gas oil, the precise blend depending on the crude, processing details etc., but common blends are (a) about 50% (e.g., in the ice range of 40-60%) by weight of vacuum residue and about 50% by weight of gas. oil and (b) about 70% (e.g., in the range of 60-80% by weight of atmospheric residue and about 30% by weight of gas oil. All these residual fuel oils give satisfactory pour points where used as the base oil in compositions according to the invention.

Some examples of compositions according to the invention will now be described by way of example. All these compositions were blended from the same additive. This was an ester prepared by reactingone molecular proportion of diethylene glycol with two moelcular proportions, of an equimolecular mixture of monochloracetic acid and a wool grease stearine which had the following inspection data:

I Acid value mg. KOH/gm 14S Saponification value mg. KOH/gm..- 158 Melting point C-.. 34 Iodine value 38 Unsaponifiables "percent" 18 This diester was used as the additive to prepare three blended fuel oils.

EXAMPLE 1 The baseoil was a mixture of 53% by weight of a Saharan vacuum residue and 47% by weight of a Middle East gas oil. The base oil had the following properties:

Density at 15 C. 0.889 Kinematic viscosity at 20 C cs 45.9 Sulphur content percent 0.9 Asphaltenes content do 0.45 Pour point C-.. 3

A blended fuel oil was produced by adding 0.2% by weight of the additive to this base oil. The pour point of this composition is given in Table I.

Table 1 Dose of Additive, percent weight 0 0.2 Pour Points, O -3 24 EXAMPLE II The base oil was a mixture of 29.3% by weight Saharan vacuum residue, 22.1% Middle East vacuum residue and 48.6% of Middle East gas oil.

A blended fuel oil was produced by adding 0.2% by weight of the additive to this base oil. The pour point of this composition is given' in Table II.

Table II Dose of Additive, percent weight 0 0. 2 Pour Points,0 3 15 EXAMPLE III The base oil was a mixture of 30% Gabon vacuum residue and 70% Gabon gas oil. It has the following A blended fuel oil was produced by adding 0.2% by It had the following Table III Dose of Additive, percent weight Pour Points, "0 .a +3

I claim:

1. A fuel oil composition which consists of a small proportion of an additive dissolved in a base oil in an amount sutficient to depress the pour point of said base oil, the additive consisting of at least one diester formed between:

(a) one molecular proportion of at least one glycol selected from the group consisting of glycols and polyglycols having 2-10 carbon atoms, and

(b) two molecular proportions of a mixture of (1) a chlorinated fatty acid having a formula CIC H COOH, where n is an integer greater than 0 and less than 11 and (2) at least one saturated fatty acid having at least carbon atoms per molecule the ratio of said chlorinated fatty acid to said at least one fatty acid being 1:%2;

and the base oil being a petroleum fuel oil which contains at least a substantial proportion of a distillation residue.

2. A composition according to claim 1, in which the glycol is one selected from the group consisting of monoethylene glycol, diethylene glycol, triethylene glycol and propylene glycol.

3. A composition according to claim 1, in which the fatty acids of item (b)2 contain at least 18 carbon atoms per molecule. a

4. A composition according to claim 1, in which the chlorinated fatty acid is monochloracetic acid.

5. A composition according to claim 4, in which the additive is the diester formed between one molecular proportion of diethylene glycol and two molecular proportions of an equimolecular mixture of monochloracetic acid and wool grease stearine.

6. A composition according to claim 1 which contains 0.0l1% by weight of additive.

7. A composition according to claim 6 which contains about 0.10.3% by weight of the additive.

8. A composition according to claim 1, in which the base oil contains 20-80% of distillation residue.

9. A composition according to claim 8, in which the base oil is a blend of vacuum residue and gas oil.

10. A composition according to claim 8, in which the base oil is a blend of atmospheric residue and gas oil.

11. A composition according to claim 10, in which the base oil contains 60-80% by weight of atmospheric residue.

12. A composition according to claim 9, in which the base oil contains -60% by weight of vacuum residue.

References Cited in the file of this patent UNITED STATES PATENTS 2,039,111 Pevere Apr. 28, 1936 2,119,718 Pevere June 7, 1938 2,138,771 Pevere Nov. 29, 1938 2,527,889 Moore et a1. Oct. 31, 1950 

1. A FUEL OIL COMPOSITION WHICH CONSISTS OF A SMALL PROPORTION OF AN ADDITIVE DISSOLVED IN A BASE OIL IN AN AMOUNT SUFFICIENT TO DEPRESS THE POUR POINT OF SAID BASE OIL, THE ADDITIVE CONSISTING OF AT LEAST ONE DIESTER FORMED BETWEEN: (A) ONE MOLECULAR PROPORTION OF AT LEAST ONE GLYCOL SELECTED FROM THE GROUP CONSISTING OF GLYCOLS AND POLYGLYCOLS HAVING 2-10 CARBON ATOMS, AND (B) TWO MOLECULAR PROPORTIONS OF A MIXTURE OF (1) A CHLORINATED FATTY ACID HAVING A FORMULA CLCH2NCOOH, WHERE N IS AN INTEGER GREATER THAN 0 AND LESS THAN 11 AND (2) AT LEAST ONE SATURATED FATTY ACID HAVING AT LEAST 10 CARBON ATOMS PER MOLECULE THE RATIO OF SAID CHLORINATED FATTY ACID TO SAID AT LEAST ONE FATTY ACID BEING 1: 1/2-2; AND THE BASE OIL BEING A PETROLEUM FUEL OIL WHICH CONTAINS AT LEAST A SUBSTANTIAL PROPORTION OF A DISTILLATION RESIDUE. 